What is the purpose of indexing in databases?

Indexing in databases primarily serves to enhance the speed of data retrieval operations. When data is indexed, it creates a data structure that allows the database management system to find and access data more quickly than it would by scanning the entire dataset.

For example, consider a book with an index at the back: instead of reading through each page to find a specific topic, one can simply refer to the index for the page numbers where that topic is discussed. Similarly, in a database, an index allows the system to locate the required records swiftly by organizing the pointers to the actual data. This is particularly valuable in large datasets where search times can significantly impact performance.

By optimizing how data is accessed, indexing can dramatically reduce query execution times, enabling more efficient data management and improved overall application performance. This efficiency gain is a critical consideration during database design, especially for applications that involve frequent querying of large volumes of data.